Process of finishing cotton yarn and the product thereof



Patented Dec. 1-2, 1939 PROCESS OF FINISHING COTTON YARN AND THE PRODUCT THEREOF William H. Fumess, Riverton,.N. J1, assignor to American Rayon Company,

Inc., Riverton,

N. .L, a corporation of New Jersey No Drawing. Application March 9, 1937,

Serial No. 129,819

. 3 Claims.

This invention relates to a process of finishing cotton yarn and the product thereof.

One of the primary objects of my invention is to impart a permanent finish to cotton yarn having aluster greater than that of mercerized yarn and of'spun rayon and very closely appreaching that of long filament rayon, for the same size and twist, this luster appearing no matter what the angle of view.

Another objectof the invention is to provide a yarn with such a finish which is flexible and soft and which in addition may have any desired elongation within, of course, practical limitations.

Another object of the invention is to provide a yarn having the foregoing characteristics and which in addition is, for all practical purposes, of uniform diameter, an achievment which, to the best of my knowledge, has nctheretofore been accomplished. Also the twist in the yarn is less readily discernible to the eye."

Still another object of the invention is to provide a process for providing such characteristics, which is simple, economical and so easy of con- 5 trol that it can be efiectively used in commercial operations.

In carrying out my invention Iproceed pref- 'erably as follows: Ifirst' draw the yarn through a'water bath containing about V per cent of a wetting agent suchya's the sulphonated aromatic compound, now on the market under the trade name "Arasklene or the sulphonated fatty acid now on the market under the trade name Avir'ol.

Without the use of such a wetting agent the maximum results will not be achieved.

I now draw the yarn through a caustic soda bath ,of approximately 300-400 grams per liter strength. Assuming that the yarn is being 0 drawn through the bath at about 22 yards per minute the travel should be about 8 to 10 feet long. This will subject the yarn sufliciently long to the caustic soda bath to" secure thorough impregnation for singles and doubles. It is, of

5 course, to be understood that there may be variations dependent upon the weight or size of the yarn, the number of plies, the twist, etc. The

proper length of time of immersion for any particular yarn. or cord may readily be determined by trial, thorough impregnation being the desideratum. I

In subjecting the wetted yarn to the caustic bath, the wetting agent largely precipitates out. On leaving the caustic soda bath, the yarn is 3 passedthrough squeeze rolls to remove excess solution and it is further run through a water bath to remove adhering caustic coda, the yarn being then again passed through squeeze rolls to remove excess liquids.

)1 The caustic soda now remaining in the yarn is that which has combined to chemically alter grams of NH3, per liter; to this add 2 litefs of a solutioncontaining 250'grams CuS'O4:5l-I2O and '68'grams of NH3, per liter; precautionarily add 2 liters of 26 B. ammonia to insure stability as against temperature conditions; and add 5 /2 liters of water; making a total of liters.

Of this combined bath, about one-half of the volume is the double salt and the other half is the tetrammonium copper sulphate. These proportions are not critical. I have obtained the best results. with about a 50-50 solution but have obtained good results with as high-as about 70 per cent double salt.-

- 'I'he time of immersion in the combined bath is, however, of substantial importance and the period is-to be determined from the standpoint of the functional results hereinafter to be mentioned. For a 50-50 bath,.with the yarn drawn therethrough at 22 yards per minute, the yarn should be immersed for a distance of about '7 feet. This will give optimum results. Here again there may be variations depending upon the proportions of the combined bath and. the particular yarn or cord being treated and again the proper period of immersioncan readily be determined by trial.

After running through the combined bath, the yarn is subjected to an acid bath such, for example, as a ten per cent sulphuric acid solution, in order to remove copper, after which'the yarn passes through a water bath and is dried.

The operation is continuous and he tension applied is preferably only that required to draw the yarn through the various baths and the drier which, of course, involves a tension infi nitely much less than the tension ordinarily applied in mercerizing. By adjustment of tension the results may be varied somewhat.

The main functions performed by the combined bath are as follows. The fuzz projecting from the yarn, relative to the body is very fine, i. e., of exceedingly small diameter. The tetrammonium copper sulphate of the combined bath immediately affects the fuzz removing the caustic soda therefrom. The double salt of the combined bath is not eifective as a cellulose solvent because of the caustic soda in the yarn. How- I additional ammonia.

tion is prepared, two mols of caustic soda to one ever, as soon as the caustic soda in the fuzz is removed therefrom by the tetrammonium copper sulphate, the double salt immediately becomes effective and dissolves the fuzz (aided by the infinistesimal amount of the double salt formed when the tetrammonium copper sulphate removes caustic soda from the fuzz). The double salt portion of the combined bath otherwise does not affect the remainder of the yarn and its, fibers because the time of immersion is not suificient to permit of the removal of the caustic soda therefrom. Here mass action plays a part because the body of the fiber and of the yarn is of appreciably greater diameterthan that of the fuzz. Since the caustic soda is not removed from'the body of the fibers and from the yarn, the double salt is ineffective as a solvent and now acts as a swelling agent.

Thus the yarn is given a dauble swelling action, namely, by the caustic soda bath and by the combined bath. This double swelling action imparts the sheen or luster hereinbefore described.

Additionally, the fuzz is removed and for all practical purposes no dissolved cellulose is left on the surface, the dissolved cellulose being in such dilute solution that it leaves the yarn and enters into the bath. This tends toward flexibility and softness. The fibers remain individual and are not tacked together.

The uniformity in diameter hereinbefore referred to isbrought about, I believe as follows. The soft portions of the untreated yarn, i. e., the slub-like portions where the fibers are well spread apart and make lumps or slubs, are in all probability more strongly affected by the solutions and on drying they contract more than the remaining portions and thus are reduced in diameter to the diameter of the remaining portions of the yarn.

Curiously enough the neps usually found associated with a bit of hull are removed in the process.

One way of preparing the double salt hereinbefore referred to is to make a solution of copper sulphate and aqua ammonia, and then add some Then a caustic soda solumol of copper sulphate. The caustic soda solution is then added and finally the needed amount of water is added. I prefer somewhere around to about grams per liter of ammonia in the combined bath to ensure stability.

In warm weather part of the water may be added in the form of ice when preparing the copper sulphate and aqua ammonia solution and when preparing the caustic soda solution to prevent the formation of copper hydroxide and to insure that the solution is essentially the double salt. i The combined bath is only negligibly affected by the caustic soda removed from the fuzz and from time to time the'proper concentration of the bath can be maintained by adding amounts of tetrammonium copper sulphate and ammonia.

In drawing the yarn through the caustic soda bath, the feed rolls may be adjusted as required in order to permit of any predetermined amount of shrinkage. In the subsequent operations the; feed rolls may be adjusted to take out any pre-l determined amount of'this shrinkage. leaving amass? behind a certain amount which will determine the elongation of the yarn. In this connection the shrinkage in the caustic soda bath manifests itself by a wool-like appearance.

If the starting yarn be one that has been mercerized, then the luster is still more enhanced.

While the invention is particularly applicable to cotton yarns for knitting and the like, it is applicable to other yarns such, for example, as spun rayon, mixed yarns, cotton cords for automobile tires, etc.

I claim:

1. In a process for treating cotton yarn, the steps of subjecting yarn to a caustic soda solution of approximately mercerizing strength and subsequently, while still containing the combined caustic soda, to a solution consisting essentially of two portions, one a solution of copper sulphate ammonia and caustic soda and the other tetrammonium copper sulpate,.and allowing the yarn to remain in said solution just long enough to remove caustic soda from the fuzz and to thereby bring about the dissolution of the fuzz,

the solution of copper sulphate ammonia and caustic soda comprising from about 50% about 70% of said solution and having a molecular ratio of one mol of copper sulphate to two mols of caustic soda and having suflicient mols of NH: to have stabality in the range of working temperature.

2. In a process for treating cotton yarn, the steps of subjecting the yarn to a caustic soda solution of approximately mercerizing strength,

washing the treated yarn with water to remove adhering caustic soda and subsequently, while still retaining the combined caustic soda in the yarn, subjecting the yarn to a solution consisting essentially of two portions, one a solution of copper sulphate, ammonia and caustic soda, with two mols of caustic soda to one of copper sulphate, and the other a solution of tetra-ammonium copper sulphate, allowing the yarn to remain in said solution suiiiciently long to remove caustic soda substantiallyonly from the fuzz to thereby dissolve the fuzz and subject the yarn otherwise to the swelling action of said solution, the yarn being run through the caustic soda bath with freedom for a predetermined shrinkage and under predetermined tension in the remaining steps. a

3. In a process for treating cotton yarn, the steps of subjecting the yarn to a caustic soda solution of approximately mercerizing strength, removing substantially all but the combined caustic soda, subsequently subjecting the yarn while still containing the combined caustic soda to a treating solution prepared by first making a solution of. copper sulphate and ammonia, then adding additional ammonia, thereafter mixing with the foregoing a solution of caustic soda so that in these combined solutions caustic soda and copper sulphate are present in the ratio of two mols of caustic soda to one vmol of copper sulphate, and thereafter mixing the foregoing with a solution of copper tetrammonium sulphate, and allowing the yarn to remain in said treating solution long enough to remove caustic soda from the fuzz and to therebybring about the dissolution of the fuzz.

WILLIAM HENRY FURNESS.

CERTIFICATE OF CORRECTION Patent No 2,185,117? December 12, 1959.

WILLIAM H. FURNESS.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows; Page 1, first column, line 55, for the words "sulphonated fatty acid" read sulphated fatty alcohol; line 57, for "coda" read soda; page 2, first column, line l9, for "dauble" read double; and second column, line 20, claim 1, for "sulpate" read su1phate;,li'ne 29, same claim, for "-stabality" read stability; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

signed and sealed this 15th day of February, A. D. 191 0 Henry Van Arsdale, (Seal) Acting Commissioner of Patents. 

